"These are products we have traditionally paid bounties for in a discretionary basis anyway, but we wanted to make that explicit," Adamski wrote.

Mozilla can deny a reward to a researcher, however, if the organization deems the person has not acted in the best interests of users, Adamski wrote.

Other parts of the program will be retained, however. A reward will still be paid even if a researcher has published information on the vulnerability or if the researcher doesn't have time to work closely with Mozilla's security team.

One of the arbitrary code execution vulnerabilities patched in Firefox earlier this week, was discovered by a 12-year-old bug hunter, who earned $3,000 from Mozilla for the find.

The flaw is identified as CVE-2010-3179 and is described as a buffer overflow and memory corruption issue, which can occur using the document.write() function.

The bug can be exploited by tricking potential victims into visiting a specially crafted Web page that crashes their browsers and potentially allows the attacker to execute malicious code on their computers.

Mozilla has expanded the scope of its vulnerability reward program and will now pay out for problems found within applications used across its websites.

Researchers could earn between US$500 and $3,000 for finding a vulnerability in one of Mozilla's web properties, depending on the severity of the flaw. Mozilla wants researchers to track down coding errors such as cross-site scripting flaws and cross-site request forgery problems. Denial-of-service bugs won't be considered since those often do not involve a technical vulnerability within a web application, Mozilla said.

"We want to encourage the discovery of security issues within our web applications with the goal of keeping our users safe," Mozilla said on its security blog. "We also want to reward security researchers for their efforts with the hope of furthering constructive security research": http://www.mozilla.org/security/bug-bounty-faq-webapp.html

Researchers should not use automated tools on the sites to find the problems, Mozilla said, as that could affect its ability to keep the sites running properly. Instead, it encouraged researchers to download the open source code for its web applications to examine the code for problems and attack the software on their own servers.

In July, Mozilla upped the reward for finding bugs in its client applications from $500 to a maximum of $3,000. The organization said it felt the need to increase the maximum bounty to ensure it was economically sustainable for people to do the research.

At the time, the program applied only to the Firefox browser, Thunderbird e-mail client, the Firefox mobile browser and other services the products rely on. Mozilla published a list of its websites that now qualify for the program, but said others will be considered, depending on the flaw. Those that definitely qualify are: